I was wondering if anyone knows what may be wrong with my car... I took it in for CEL and there was a random misfire (PO300), and I got the spark plugs changed. I went to pick it up and it was stalling really bad. The mechanics cleaned out the EGR and it ran ok for 2 drives. The CEL light came on again and the code was PO507 (RPM higher then expected).They cleaned out the throttle body and adjusted the throttle cable. After they did that the CEL was off but the car would only idle at normal RPM after it surges twice. I don't know what the hell is going on and they don't know either. They told me it might be the IAC motor but they can't fix it. Could it be something else? And is the IAC motor cleanable???
Thanks

I would bring it to other tech. Tamperring with idle air control system required some knowledge. I think your mechanic mess the TP sensor setting. Incorrect TP setting will cause engine to surge. I would have it recheck by a technician then work on high idle problem. High idle can be caused by high idle setting, air leak or stuck open idle air control valve.